Universal completions of concrete categories
For every concerete category (A,U) over a complete base category X, Ch. Ehresmann has constructed a concrete completion. The objects of his completion are obtained by a transfinite process. J Adámek and V. Koubek have been able to obtain the objects of such a completion in one step, but still need a transfinite process to obtain the morphisms. In this paper a one-step-construction for such a completion is provided. The latter two completions are characterized by the obvious universal property, hence equivalent. The first completion is different.
KeywordsSmall Category Unique Extension Complete Category Canonical Embedding Structure Source
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